Can't see new SSD when connected via internal SATA port

I just bought a new Samsung SSD 830 and installed it my 13" MacBook Pro (Mid 2010) in the hard disk bay, replacing the drive that was there (I actually have a second drive in the optical drive's slot). Unfortunately, when I started up my computer (from the other drive I have), I can't see the SSD in System Information (formerly Profiler) or Disk Utility. However, I see the drive fine when using a SATA-to-USB adapter and I also am able to see the old hard disk when it is connected via the internal SATA, so the internal wiring seems to be fine. Thus: * HDD via USB: works * SSD via USB: works * HDD via internal SATA: works * SSD via internal SATA: completely broken Anyone have ideas for a fix?